SSS 2010-07-22（在线收听）

Imagine if before you took each step, your guts lurched up into your throat. Well, caterpillars don’t have to imagine—they take such drastic steps every day.

Researchers were interested in how fluids move around inside a caterpillar. So they put one on a treadmill and x rayed it while it walked. Caterpillars move by a wave that starts at the back end of their body and sweeps through each segment until it reaches the head, pushing it forward. The scientists had assumed that the guts were squished or squeezed or wobbled about like a bowl of jello in a moving car.

They were surprised instead to find that the insects move via an integrated, two-stage system in which their guts go forward before their outer body does. So, their innards do slide into their throat, but it’s a controlled glide. The finding was published online in the journal Current Biology.

The researchers describe the way of walking as “unlike any form of legged locomotion previously reported.” The discovery is already being investigated by engineers for possible soft-bodied robots. Because no guts, no glory.

Thanks for the minute for Scientific American’s 60-Second Science. I’m Molly Webster